Electric clock



Aug. 12, 1941.

J. W. HOBBS ELECTRIC CLOCK Filed March 3, 1939 2 Sheets-Sheet l Jo/mAug. 12, 1941. J. w. HOBBS ELECTRIC cnocx Filed March 3, 1959 2Sheets-Sheet 2 Patented Aug. 12, 1941 OFFICE 2,252,375 ELECTRIC CLOCKJohn W. Hobbs, Springfield, Ill., assignor to John W. Hobbs Corporation,Springfield, 111., a corporation of Delaware Applieation. March 3, 1939,Serial No. 259,535}

12 Claims. .(Cl. 185-40) The present invention relates in general toelectric clocks of the type adapted for use, in connection withvehicles, such as automobiles, and is more particularly concerned withspringactuated clocks Which are arranged to be automatically wound by anelectrically actuated rewinding mechanism.

In general, clocks of this type embody a ratchet wheel which isconnected with the main driving shaft of the timing mechanism andarranged to be actuated through suitable pawls carried on a movablearmature by a tension spring connected to the armature. The pawls engagethe ratchet wheel for driving it in a forward timing direction.Associated with the armature is a suitable electro-magnet for actuatingthe armature to a new position for tensioning the driving spring,whenever the driving spring has reached a predetermined unstressedcondition.

The rewinding of the clock is automatically accomplished by means of aswitch arranged to be actuated in response to the movement of thearmature, so that as the armature reaches a position in which thedriving spring is in an unstressed or run-down condition, the switch issnapped to closed position to energize the electro-magn'et and returnthe armature to a position wherein the driving spring is again stressed,and in which the spring may again operate to drive the timing mechanism.At this position, the movement of the armature operates to open theswitch and demagnetize the electro-magnet.

While such an arrangement works satisfactorily under maintained voltageconditions, conditions may prevail when operating the clock from astorage battery of an automobile which will result in unsatisfactoryoperation of the rewinding mechanism. For example, when the voltage ofthe battery of an automobile is below normal, or during starting of thecar, particularly in the winter time, there may be times when there isinsufiicient voltage to energize the electro-magnet sufiiciently to movethe armature to a position wherein it will open the de-energizing switchin'circuit with the electro-magnet wind-. I

ing. Under such conditions, the electro-magnet winding will be energizedfor an abnormal period of time, with the result thatthe coil of theelectro-magnet becomes overheated and there is the possibility of itsbeing burned out or otherwise damaged.

Various devices for opening the circuit under such conditions have beensuggested, such as thermostatically operated switches, fuses and thelike.

In the present invention, it is a primary object to provide a maincontrol switch which will be positively opened independently of thearmature position, especially a control switch mechanism which will openthe energizing circuit of the electro-magnetic rewind mechanism, whenthere is insufficient voltage to actuate the armature to a positioncorresponding to the fully stressed condition of the main drivingspring.

A further object of the invention is to provide improved means foractuating the switch contacts to closed position in response to thearmature reaching a position corresponding with a run-down condition ofa main winding spring, the actuating means for the contacts being soarranged as to assure operation of the switch contacts by the reducedenergy stored in the spring.

It is another object of the invention to provide control contacts forcontrolling the rewinding mechanism which are so arranged that thecontacts will be opened and closed in such a manner as to cause thecontact surfaces to mutually wipe each other, thus keeping the contactsclean and in good operating condition.

It is a further object of the invention to provide a control switch forthe rewinding mechanism which is arranged to be closed by the movementof the armature during driving of the timing mechanism by the mainspring, wherein the contacts will be closed with a snap action, and inwhich pressure will be applied by the main driving spring against thecontacts to subsequently force them together, in the event that thecircuit of the electro-magnetic rewinding mechanism fails to be closeddue to dirt, corrosion or other material having accumulated on thecontacts to prevent completing the circuit under normal pressure of thecontacts.

Still another object of the invention is to provide in connection withthe control switch for the rewinding mechanism, novel resetting meansfor actuating the switch contacts to open position, wherein theresetting operation is motivated by the electro-magnet for attractingthe armature during the rewinding operation.

It is also an object of the invention to improve the operation of theelectro-magnet and associated armature by providing projecting polarportions which normally extend into the air gap between the armature andelectro-magnet, when the clock is in substantially run-down condition,thereby securing a magnetic path of relatively lower reluctance to theflow of magnetic flux between the poles of the armature and theelectromagnet. Such an arrangement gives the rewinding mechanism morepositive actuating characteristics.

Other objects and features of the invention will more fully appear fromthe following de tailed description, taken in connection with theaccompanying drawings, which illustrate several embodiments thereof, andin which:

Figure 1 is a side elevational view of an electric clock embodying thefeatures of the present invention, taken on the side of theelectro-magnet to show the cooperative relationship between theelectro-magnet poles and the armature poles, when the rewindingmechanism is in substantially run-down condition;

Figure 2 is a transverse sectional view showing the positions of thecontrol switch mechanism and the armature, when the rewinding mecha nismhas been energized and the driving spring is in fully stressedcondition, taken substantially on the line 11-41 of Figure 1;

Figure 3 is a similar View showing the armature approaching a positionin which the driving spring is reaching unwound condition, the switchingcontacts having been moved to a position where they will pass throughdead center and be snapped closed;

Figure 4 is a similar view showing the armature at the limit of itsmovement by the main driving spring, the contacts of the switchmechanism having been snapped to closed position for completing thecircuit through the rewinding electromagnet;

Figure 5 is a side elevational view of the clock looking toward theswitching mechanism;

Figure 6 is an enlarged detailed view showing the manner in which thedriving mechanism is connected with the shaft of the timing mechanismthrough a friction drive;

Figure '7 is an enlarged fragmentary plan view showing a modified formof actuating mechanism for opening the switch contacts; and

Figure 8 is a similar view showing another construction of mechanism foropening the switch contacts.

As shown on the drawings:

Referring to Figures 1 and 5, the mechanism of the present invention ismounted on a frame structure comprising a back plate H), a front plateH, and an intermediate plate it, these plates being supported inspaced-apart relation by suitably distanced pieces !3 arranged tomaintain the plates in rigid assembled relation. The frame structurealso forms a support for a conventional timing mechanism (not shown)include;

ing a gear train for actuating the hour and minute hands in proper speedratio, and a conventional escapement mechanism (not shown) forcontrolling the operation of the driving mechanism.

The timing train is associated with a shaft M which is rotatablysupported in the plate I I and provided with a spring frictionconnection for engaging the surface of a gear !8, as shown in Figure 6.This arrangement is conventional and permits setting movements of thetiming gears and hands with reference to the driving mechanism. The gear56, which is drivingly connected with a conventional escapementmechanism, is threadedly secured to one end of a driving shaft llrotatably supported in the back plate I!) and a bearing sleeve 98 whichis supported at one end on the middle plate l2.

The outermost end of the shaft l'l carrie a ratchet driving wheel !9arranged to be driven in one direction by a pair of push-pawls and 2| onan armature 22. This armature embodies a pair of radially extending arm23 and 24 in angularly disposed relation. The armature is provided witha tubular hub portion 25 which is rotatably mounted on the sleevebearing I8, this hub portion serving as a spring drum for a main drivingspring 26 coiled therearound, the spring being anchored at one end tothe intermediate plate I2 and at its other end to the armature. Thespring is so arranged that when the armature is rotated in a clockwisedirection as viewed in Figures 2, 3 and 4, the main driving spring 26will be tensioned and the pawls 20 and 2| will ride over the ratchetteeth of the ratchet wheel 59. Rotation of the ratchet wheel in theopposite direction is prevented by means of a detent pawl 27 pivotallymounted on the back plate l0 and provided with a suitable spring foractuating it into engagement with the ratchet wheel teeth.

When the armature is released, the pawls, by virtue of their engagementwith the teeth on the ratchet wheel, will carry the ratchet wheel withthem as the driving mechanism is moved under the force of the maindriving spring 26. This driving operation is, of course, controlled bythe escapement mechanism in the usual manner.

Provision is made for electrically actuating the armature in a directionto tension the main driving spring, that is, to move the armature inclockwise direction. For this purpose, there is disposed for operativeassociation with the armature an electro-magnet having an energizingcoil 28 wound on a suitable magnetic core. This core is fitted at eachend with a pole assembly composed of a pair of nested U-shaped members29 and 39 having their leg portions in spaced-apart relation and theirleg edges arcuate, as shown at 3!.

The electro-magnet thus formed is secured to the front plate as byrivets 32 which extend through the plate and engage the pole assembly ateach end of the electro-magnet. It will be noted that the intermediateplate is discontinuedto provide space for the electro-magnet, and thatthe electro-magnet projects past the intermediate plate and has itsopposite side from the side which is secured disposed adjacent thebackplate It. The armature arms 23 and 24 are deflected to respectivelyform an armature pole 33 for cooperation with the associated pole of theelectro-ma-gnet. Transversely, the armature poles are arcuate to conformto the arcuate edges of the electro-magnet poles, and each armature poleis provided with a laterally extending tapered projecting portion 34which is arranged to extend into the gap between the associated polesand de-- fine a magnetic path of decreased reluctancecompared to thatwhich would ordinarily be formed if the pole did not include theextention. In other Words, the polar projection establishes a flux paththrough the gap which augments the operation of the armature and enablesit to be more readily attracted during the beginning of the rewindingoperation, particularly when the energizin voltage of the coil is low.

Movement of the armature away from the electro-magnet poles, that is,during the driving operation of the timing mechanism, is limited by astruck up portion 35 in the intermediate plate, this portion defining astop in the path of movement of the outermost end of the arm 23 of thearmature. It will be seen that the assembly is simplified and the depthof the timing mechanism may be decreased by virtue of having thearmature arms 23 and 24 disposed in angular relation. This enables theelectro-magnet to be placed at one side of the driving shaft I1 andeliminates the necessity of having to discontinue this shaft directlyover the electro-magnet or provide for its passage through the coil andcore thereof, as in the usual arrangement.

For controlling the actuation of the rewinding mechanism, a switch isprovided in the space between the front and intermediate frame plates Hand I2. As shown in Figures 2, 3, and 4,. this switch includes a pair ofcontacts 35 and 31 which are arranged for relative movement into closedand opened relation. The contact 31 is mounted adjacent one end of aflexible strip 38, the contact being at the free end of the strip. Atits other end, the strip 38 is anchored between a pair of insulatingmembers 39 and 40 which are supportingly mounted on a suitable bracket4| secured to the intermediate plate. The contact 35 is actuated by amulti-armed lever having a pivotal mounting as shown at 42 on theintermediate plate and comprising the angularly disposed arms 43, 44 and45, the contact 35 being carried at the free end of the arm 45. Movementof the contact arm 45 in a direction to move the contact 35 away fromthe contact 31 to open position is limited by a bracket 43 secured tothe intermediate plate and having an upstanding leg extending into thepath of movement of the arm. 45, the upstanding leg being provided witha pad 41 of cushioning material, such as felt for cushioning the impactof the arm against the stop and rendering the impact substantiallynoiseless.

The arm 43, at its outermost end, is bifur cated to provide a V-notch43. For imparting a snap-action movement of the contact 36 from adead-center position either toward the stop 46 or toward the contact 37,there is associated with the arm 43 a second arm 49 which is pivotedadjacent one end for swinging movement in a post or bracket 53 on theintermediate plate. At its other end, the arm 49 is provided with a headportion 5i defining a knife edge arranged to seat" in the V-notch 48 ofthe arm 43. The head 5| is retained in the notch 48 by means of a U-shaped retaining member 52 having its legs respectively disposed overthe opposite end surfaces of the arm 43. A spring 53 surrounds the arm49 with one end bearing against the post 50 and its other end bearingagainst the bridging portion of the retaining member 52, this springacting to move the multi-armed lever with a snap action in the oppositedirections from the dead-center position in which the arms 43 and 49 arein axial alignment.

Means are provided for swinging the multiarmed lever in response tomovements of the armature during the driving and rewinding operations.For this purpose, closing of the contacts and 31 is accomplished byproviding a pair of radially aligned spaced apart pins 54 and 55 whichwith the associated part of the armature form in effect a crank ofvariable throw, since the pins arearranged to successively engage thearm 44 during rotational movement of the armature in a counter-clockwisedirection while driving the clock, as shown in Figures 2, 3 and 4.

With the contacts 351 and 31 in fully opened position, as shown inFigure 2, it will be apparent that as the armature moves incounter-clockwise direction, the pin 54 will be the first pin to engage.the lever arm 44. Since the pin 54 is disposed.

relatively closely to the center of rotation of the armature, this pinwill strike the arm 44 at its extreme end portion, with the result thatthe angular, movement of the arm 44 will be relatively slower than theangular movement of the armature. Moreover, due to the relatively shorteffective lever arm of the pin 54 and the relatively long effectivelever arm of the arm 44, the forces applied by the pin 54 under thiscondition will be increased, thus assuring movement of the contact 36during a weakened condition of the main driving spring 26 which isapproaching an unwound condition.

The pin 54 is arranged to carry the arms 43 and 49 to a positionapproaching dead-center.

At this point in the movement, the pin 55 engages the lever arm 44 at apoint spaced from its outer end, and as the movement of the armaturecontinues the pin 54 disengages the lever 44. Since the pin 55 isradially spaced a greater distance from the center of rotation of thearmature than the pin 54, it will be seen that the angular speed ofrotation of the multi-armed lever will be increased in relation to theangular movement of the armature. Thus, it will take only a very smallangular movement of the armature to actuate the arms 43 and 49 through adead-center position. As soon as the arms pass through dead-centerposition, the spring 53 is effective to actuate the contact 33 intoengagement with the contact 31 with a snap action.

Since the contact 31 is not rigidly supported, the strip 38 will beflexed slightly and thus cause a wiping movement between the engagedsurfaces of the contacts 36 and 31 to provide a good electrical contact.There may be times, however, when the circuit is not completed due toimproper contact between the contacts 35 and 31. Under such conditions,the armature will continue to move in counter-clockwise direction untilthe pin 55 again reaches the lever arm 44, whereupon the main springacts to apply increased pressure between the contacts and force theminto good surface engagement.

The rewinding operation is now ready to take place, and as soon as thecontacts 36 and 3'! are in closed position, the circuit is completed tothe actuating coil 28 of the electro-magnet. This circuit may be from asource of power, such as a storage battery 55 which may have one of itsterminals connected, as by a connection 51, which may be a conductor ormay be a ground circuit from this terminal of the battery. The otherterminal of the battery is connected through a conductor 58 to one endof the actuating coil 28, the other end of this coil being connectedthrough a suitable conductor 59 to the contact supporting strip 38. Thecircuit then continues through the contacts 36 and 31 to the multi-armedlever which is connected from a point adjacent its pivot by a bridgingconductor 53!] to the post 50 which is in grounded connection with theframe plate [2, from whence the circuit is completed through the framestructure back to the grounded side of the battery.

The circuit thus being completed through the actuating coil, theelectro-magnet is energized and functions to attract the armature,moving it in a clockwise direction. This movement of the armature actsto again tension the main driving spring 25. Provision is made foropening the contacts 35 and 31 by resetting themovable contact 36 to theposition engaging the stop 46. The resetting operation is accomplishedby means of a third pin 8! which is arranged to engage the lever 44 onthe opposite side from the side which is engaged by the pins 54 and 55.With this resetting arrangement, in which case the pin 6| will move themulti-armed lever in a counter-clockwise direction through deadcenterposition, it is necessary that the armature during the rewindingoperation be moved to a position corresponding to the fully stressedcondition of the main driving spring. With sufficient voltage on thebattery, the armature will always be moved to such position, but in theevent that the battery voltage is low, which may occur during coldweather or during the starting operations of an automobile engine, theelectromagnet may not be sufiiciently energized to move the armaturesufiiciently to cause resetting of the contact 36 to opened position.

In order to assure that the switch contacts 36 and 31 are actuated toopened position and prevent continuous energization of the electromagnetcoil, which might result in the burning out of this coil, directresetting means are provided for resetting the contact 36 to openposition independently of the position of the armature during therewinding operation.

The mechanism for independently resetting the contact 36 may assumevarious constructional forms or arrangements. Figures 2, 3 and 4illustrate one construction in which a small pivotally mounted armatureS2 is associated with one of the poles of the electro-magnet. Thisarmature is pivotally mounted on the intermediate plate, as shown at 63,and is normally biased for movement in a counter-clockwise direction bya suitable spring 64, movement in this direction being limited by a stopwhich may comprise an extension 55 on the bracket M. In this position,the armature is spaced away from the associated pole of theelectro-magnet. However, as soon as the contacts 36 and 3'! are closedto energize the actuating coil of the rewinding mechanism, the armature62 will be moved in a clockwise direction toward the associated pole ofthe electro-magnet.

As a result of the clockwise movement of the armature, an angularlydisposed arm 65 of insulating material, which is carried by thearmature, is moved into engagement with the outermost end of theflexible strip 38 carrying the contact 31. If desired, the outermost endof the flexible strip 38 may be rounded, as shown at El, to provide acurved surface for decreasing the frictional engagement of theinsulating member therewith. As a result, the contacts 3? and 3% aremoved as a unit, and the throw of the member 65 is sufficient to carrythese contacts to a position wherein the multi-armed lever will passthrough dead-center position and the contact 35 actuated withsnap-action to fully opened position against the stop 45. Of course,this opens the energizing circuit of the coil 28. The poles of theelectro-magnet, now being de-energized, permit the armature 62 to bemoved by the spring 54 back against the stop 65, thus permitting thecontact 31 again to assume its normal position.

It will be noted that during the resetting operation in this manner,when the contacts 35 and 3'! are being moved as a unit, these contacts,due to their support on arms which will move about different centers,will cause wiping action between the contacts. It will thus be apparentthat wiping action is obtained between the contacts 36 and 37 duringboth opening and closing movements, thus tending to keep these contactsclean at all times, so that good electrical contact may be establishedwhen the contacts are closed.

Referring to Figure '7, a modified form of resetting mechanism is shown.In this form, the armature 52a is supported for rectilinear movementstoward and away from the adjacent pole of the electro-magnet. Thearmature is provided with a supporting stem 68 mounted for longitudinalmovement in upright deflected ends 69 and 10 of a supporting bracket Hsecured to the intermediate plate. The armature is biased into abuttingengagement with the leg 10 of the bracket by a spring 12 surrounding thestem 63, one end of this spring engaging the leg 79 and the other endengaging a collar 13 carried by the stem. Movement of the stem, when thearmature 62a is attracted toward the adjacent pole of the electro-magnetis transmitted to the end of the flexible strip 33 by means of a bellcrank i i having a pivotal mounting, as shown at 75, on the intermediateplate. One arm of this bell crank, which is preferably made of aninsulating material, is normally engaged by a pin 16 carried by the stem63. The other arm of the bell crank engages the outer end of theflexible strip 38.

It will therefore be apparent that when the contacts 36 and 3? areengaged and the armature 62a is attracted, the bell crank will bepivotally moved in a counter-clockwise direction and deflect theflexible support 38, so as to move the contacts 35 and 37 in unison andcause resetting of the multi-armed lever to opened position of thecontact 35.

Another modification of the resetting mechanism is shown in Figure 8. Inthis arrangement, the armature, as indicated at 621), is supported atthe free end of a support H which is pivotally mounted at its other end,as shown at 78, on the intermediate plate, the pivot of this supportbeing disposed adjacent the pivotal mounting of the multi-armed lever.It will be noted that the outermost end of the support ll underlies thefree end of the flexible strip 38 and that this end of the support isprovided with a block 19 of insulating material. This block has a curvedcam surface 80 which engages the free end of the flexible strip 38. Itwill be noted that this cam surface is so arranged that as the armaturebegins its movement toward the associated pole of the electromagnet,this being the time when the electrical attraction is least, there willbe very little movement or flexing of the strip 38. However, as thearmature approaches the associated magnet pole, the throw of the cam isgradually increased as the attractive forces are increased. In thisarrangement, the spring effect of the strip 38 is utilized to return thearmature to normal position away from the electro-"nagnetic pole, whereit may be arranged to engage a suitable stop 8i which may, if desired,be one of the distance pieces $3 for interconnecting the frame plates.

From the foregoing description, it will be apparent that the hereindescribed invention provides in a spring-driven clock or timing devicean improved rewinding mechanism which embodies an improved arrangementof a rewinding electromagnet and armature, wherein projections areprovided for extending into the gap between the electro-magnet poles andthe armature poles, when the clock is in substantially run-downcondition, thus providing and determining a magnetic path of decreasedreluctance; which has improved contact actuating means for controllingthe rewinding operation, particularly when the battery or supply voltageis low; which utilizes novel pin arrangements for actuating the switchcontacts into open and closed positions in responseto armaturemovements; provides an improved switch having contactsarranged tobeengaged and-disengaged with wiping movement, so as to :maintain thecontacts in clean condition at all times; and which embodies an improvedmechanism for positively opening the control contacts for resetting thecontacts to open position, independently of the position of thearmature, this resetting mechanism being actuated magnetically from oneof .the poles of the rewinding electro-magnet.

It is, of course, to be understood that although I have described indetail several embodiments of my invention, the invention is not to bethus limited but only insofar as defined by the scope and spirit of theappended claims.

I claimas my invention:

1. ,A timing device including a driving mechanism having an actuatingspring, electrically operable. means for intermittently stressing'saidspring, a circuit connection to said means, a switch in said circuitarranged to be opened by the operation of said means'when substantiallyfully stressed condition of the spring is reached, and auxiliary meansmagnetically actuated by said first means for opening said switch in theevent that the first means is energized insuiiiciently to fully stressthe spring.

2. In a timing device, a movably mounted armature, a spring normallyacting to move the armature in a direction for driving the device, anelectro-magnet"energizable to move the armature in a non-drivingdirection for stressing said spring, an energizing circuit for saidelectromagnet, a switch having contacts in said circuit arranged to beclosed in response to armature movement to a position in which-thespring is substantially unstressed, and auxiliary means magneticallyoperable by said electro-magnet, when it is energized, for opening thecontacts of said switch.

3. In a spring driven timing device, a rewinding mechanism forintermittently stressing said spring and including an actuatingelectro-magnet, an energizing circuit for said magnet, a switch havingcontacts for normally opening and closing said circuit in response tooperation of the rewinding mechanism, and auxiliary means actuated bysaid electro-magnet for opening said contacts to terminate eachrewinding operation of said mechanism in the event of failure of therewinding mechanism to open said contacts.

4. In a spring driven timing device, a rewinding mechanism comprising anelectro-magnet including a pair of field poles, a rotatably mountedarmature operatively associated with said poles and normally biased bysaid spring for movement away from said poles, said armature being movedin the opposite direction when the electro-magnet is energized, anenergizing circuit for said electro-magnet, a switch having contacts insaid circuit arranged to be closed in response to a predeterminedmovement of the armature away from said field poles, and auxiliary meansfor actuating the contacts to open position independ ently of said'firstarmature in response to the energization of said electro-magnet andincluding a second armature operatively associated with only one of saidfield poles.

5. In a timing device, a driving mechanism havingan actuating spring,electrically operable means including an operating coil forintermittently stressing said spring, a supply circuit for said coil,and a control switch in said circuit comprising av pair of contacts, apivotally mounted support for one of said contacts swingable in reverseddirections through a dead-center position between fully opened and fullyclosed relation, with respect to the other of said contacts, springmeans for biasing the support away from its dead center position, andmeans operative for transmitting driving movements of the mechan'ism tothe support for moving the support in a contact-closing direction, saidoperating means being so arranged that the ratio between the movementsof the mechanism and the support will initially be of one value untilthe support approaches its dead-center position, and another value asthe support is moved through its deadcenter position, said meanscomprising a pair of support contacting members moved by said mechanismand having diiferent effective lever arms;

6. In a timing device, .a spring actuated driving mechanism including arotatable member, electrical rewind mechanism for rewinding the drivingmechanism. and having an operating coil, asupply circuit for said coil,a control switch in said circuit including a pair of contacts, apivotally mounted support forone of said contacts including an actuatingarm, a pair of radially spaced pins carried by said member arranged tosuccessively engage the actuating arm during driving movement of thedriving mechanism and acting to move said support in contact-closingdirection, the innermost of the pins engaging the arm prior to itsengagement by the outermost of the pins.

7. In a spring actuated timing device, an electric rewind mechanism forintermittently stressing said spring, said rewind mechanism including anactuating coil, a switch for controlling said coil arranged to benormally opened in response to the operation of the rewind mechanism,said switch comprising a pivotally supported first contact arranged forsnap movements to either side of a dead-center position, a resilientlysupported second contact engageable by the first contact when the firstcontact is moved to one side of its dead center, and auxiliary meansoperable independently of the rewind mechanism and including an armatureactuated by said coil for moving the second contact towards the firstcontact to cause simultaneous movement of the engaged contacts until thefirst contact has passed through its dead center, whereupon the firstcontact is snapped to open position on the other side of its deadcenter.

8. In a clock, a movable member, a driving spring biasing said memberfor movement in one direction, electro-magnetic means intermittentlyenergizable to move the member in an opposite direction and stress thedriving spring, contacts normally actuable in response to the movementsof said member for controlling the connection and disconnection of saidelectro-magnetic means relative to an energizing circuit, and auxiliarymechanism for actuating the contacts from closed to open positionindependently of their actuation by said member, each time saidelectro-magnetic means is energized, said mechanism including a membermagnetically influenced by said electromagnetic means.

9. In a timing device, a pivoted armature, a

spring for driving said device, said spring normally biasing thearmature for movement in one direction, an electro-magnet energizable tomove the armature in an opposite direction for stressing said spring, anenergizing circuit for said electro-magnet, switch means having contactsfor controlling said circuit, switch operating means including a pivotedarm biased for movement to opposite sides of a dead-center position forrespectively opening and closing the switch contacts, means carried bythe armature for actuating said arm through its dead-center position,said means including a pair of radially spaced projections forsuccessively engaging the arm during movement of the armature in onedirection, the innermost projection initially engaging the arm and theoutermost projection being arranged to engage the arm when it isadjacent its dead-center position.

10. A timing device comprising a driving member actuated in onedirection by a spring, electromagnetic means including a coilenergizable to intermittently actuate the member in a direction tostress said spring, a supply circuit for said coil, a control switch insaid circuit including a pair of contacts, a pivotal support for one ofsaid contacts arranged for snap movements to either side of adead-center position, a flexible support for the other of said contacts,means for moving said one of the contacts through dead-center positionin a direction toward the'other contact in response to movement of thedriving member by said spring, and means independently actuated by theenergization of said coil for flexing the support of said other contactto move both contacts in a reversed direction with respect to theclosing direction of said one contact, and carry said one of thecontacts through its dead-center position to enable snap movementthereof to open position.

11. In a, spring actuated timing device, an electric rewind mechanismfor intermittently stressing said spring, said rewind mechanismincluding an actuating coil, a switch for controlling said coil arrangedto be opened in response to the operation of the rewind mechanism, saidswitch comprising a pivotally supported first contact arranged for snapmovements to either side of a dead-center position, a resilientlysupported second contact engageable by the first contact when the firstcontact is moved to one side of its dead center, an armature moved inresponse to the energization of said coil, and a cam surface movable inresponse to the movement of said armature, said surface being arrangedto simultaneously move the engaged contacts in a direction to carry thefirst contact past its dead-center position and enable it to snap toopen position on the other side of its dead center.

12. In a spring actuated timing device, an electric rewind mechanism forintermittently stressing said spring, said rewind mechanism including anactuating coil, a switch for controlling said coil arranged to be openedin response to the operation of the rewind mechanism, said switchcomprising a pivotally supported first contact arranged for snapmovements to either side of a dead-center position, a resilientlysupported second contact engageable by the first contact when the firstcontact is moved to one side of its dead center, an armature supportedfor movement in response to the energization of said coil, and a cammember moved by said armature, said cam having a surface arranged tomove both the engaged contacts in a direction to carry the first contactin an opening direction past its deadcenter position, said cam surfacebeing arranged to move the contacts at an accelerating rate of movement.

JOHN W. HOBBS.

